1. Field of the Invention
This invention relates to a remotely controlled television camera provided for observation, monitoring and/or recording of its surrounding scenes.
2. Description of the Prior Art
A remotely controlled television camera used for observation of its surrounding scenes is normally mounted on a remotely controlled pan-tilt head and is equipped with a remotely controlled motorized zoom lens. The operator, remotely controlling the positioning of the camera for monitoring people and other objects, may have on occasion difficulties in identifying the position to which the lens of the camera is directed, especially when the zoom lens is set to its telephoto state. This is because the angle of view of the telephoto lens is narrow and this magnifies the observed scene, displaying only a small portion of the entire view, thereby removing recognizable or identifiable landmarks from the display. Therefore, an operator viewing such magnified scene from a crowded sport stadium becomes confused and does not know to which direction to pan or tilt the camera in order to find an object he intends to monitor.
On the other hand, observing the scene via the wide angle lens provides the operator with the wide overall view, which makes it possible to identify the direction of the lens. Therefore an operator of a remotely controlled television camera attempting to focus on a specific object repeatedly shifts the motorized zoom lens of the camera back and forth from telephoto to a vide angle in order to identify the camera direction and coordinate which is laborious and time consuming, and results in an inefficient observation process.
Some remotely controlled television cameras may further comprise a switchover circuit and a mechanism to switchover a camera head from color observation of well-illuminated areas during daytime to black/white observation of low level illuminated areas during nighttime. The circuit for a return switchover back from night to day observation requires a manual command by an operator, because the camera illumination sensing circuits fed by black/white signals cannot precisely identify when the observed area is sufficiently illuminated for color observation. In large systems, such manual recall command to return many cameras back to color observation is inefficient, laborious and time consuming.